'\" t
'\"! tbl | mmdoc
'\"macro stdmacro
.ds Vn Version 1.2
.ds Dt 24 September 1999
.ds Re Release 1.2.1
.ds Dp Jan 14 18:30
.ds Dm 01 getminmax
.ds Xs 43140 6 getminmax.gl
.TH GLGETMINMAX 3G
.SH NAME
.B "glGetMinmax
\- get minimum and maximum pixel values

.SH C SPECIFICATION
void \f3glGetMinmax\fP(
GLenum \fItarget\fP,
.nf
.ta \w'\f3void \fPglGetMinmax( 'u
	GLboolean \fIreset\fP,
	GLenum \fIformat\fP,
	GLenum \fItypes\fP,
	GLvoid \fI*values\fP )
.fi

.SH PARAMETERS
.TP \w'\f2target\fP\ \ 'u 
\f2target\fP
Must be
\%\f3GL_MINMAX\fP.
.TP
\f2reset\fP
If \%\f3GL_TRUE\fP, all entries in the minmax table that are actually
returned are reset to their initial values.  (Other entries are unaltered.)
If \%\f3GL_FALSE\fP, the minmax table is unaltered.
.TP
\f2format\fP
The  of the data to be returned in \f2values\fP.
Must be one of
\%\f3GL_RED\fP,
\%\f3GL_GREEN\fP,
\%\f3GL_BLUE\fP,
\%\f3GL_ALPHA\fP,
\%\f3GL_RGB\fP,
\%\f3GL_BGR\fP,
\%\f3GL_RGBA\fP,
\%\f3GL_BGRA\fP,
\%\f3GL_LUMINANCE\fP, or
\%\f3GL_LUMINANCE_ALPHA\fP.
.TP
\f2types\fP
The type of the data to be returned in \f2values\fP.
Symbolic constants
\%\f3GL_UNSIGNED_BYTE\fP,
\%\f3GL_BYTE\fP,
\%\f3GL_BITMAP\fP,
\%\f3GL_UNSIGNED_SHORT\fP,
\%\f3GL_SHORT\fP,
\%\f3GL_UNSIGNED_INT\fP,
\%\f3GL_INT\fP,
\%\f3GL_FLOAT\fP,
\%\f3GL_UNSIGNED_BYTE_3_3_2\fP,
\%\f3GL_UNSIGNED_BYTE_2_3_3_REV\fP,
\%\f3GL_UNSIGNED_SHORT_5_6_5\fP,
\%\f3GL_UNSIGNED_SHORT_5_6_5_REV\fP,
\%\f3GL_UNSIGNED_SHORT_4_4_4_4\fP,
\%\f3GL_UNSIGNED_SHORT_4_4_4_4_REV\fP,
\%\f3GL_UNSIGNED_SHORT_5_5_5_1\fP,
\%\f3GL_UNSIGNED_SHORT_1_5_5_5_REV\fP,
\%\f3GL_UNSIGNED_INT_8_8_8_8\fP,
\%\f3GL_UNSIGNED_INT_8_8_8_8_REV\fP,
\%\f3GL_UNSIGNED_INT_10_10_10_2\fP, and
\%\f3GL_UNSIGNED_INT_2_10_10_10_REV\fP
are accepted.
.TP
\f2values\fP
A pointer to storage for the returned values.
.SH DESCRIPTION
\%\f3glGetMinmax\fP returns the accumulated minimum and maximum pixel values (computed on a
per-component basis) in a one-dimensional image of width 2.  The first set
of return values are the minima, and the second set of return values
are the maxima.
The  of the return values is determined by \f2format\fP, and their type is
determined by \f2types\fP.
.PP
No pixel transfer operations are performed on the return values, but pixel
storage modes that are applicable to 1-dimensional images are performed.
Color components that are requested in the specified \f2format\fP, but that
are not included in the internal  of the minmax table, are
returned as zero.  The assignment of internal color components to the
components requested by \f2format\fP are as follows:
.sp
.TS
center;
lb lb
l l.
_
Internal Component	Resulting Component
_
Red	Red
Green	Green
Blue	Blue
Alpha	Alpha
Luminance	Red
_
.TE

.PP
If \f2reset\fP is \%\f3GL_TRUE\fP, the minmax table entries corresponding
to the return values are reset to their initial
values.  Minimum and maximum values that are not returned are not
modified, even if \f2reset\fP is \%\f3GL_TRUE\fP.
.SH NOTES
\%\f3glGetMinmax\fP is present only if \%\f3GL_ARB_imaging\fP is returned when \%\f3glGetString\fP
is called with an argument of \%\f3GL_EXTENSIONS\fP.
.SH ERRORS
\%\f3GL_INVALID_ENUM\fP is generated if \f2target\fP is not \%\f3GL_MINMAX\fP.
.P
\%\f3GL_INVALID_ENUM\fP is generated if \f2format\fP is not one of the allowable
values.
.P
\%\f3GL_INVALID_ENUM\fP is generated if \f2types\fP is not one of the allowable
values.
.P
\%\f3GL_INVALID_OPERATION\fP is generated if \%\f3glGetMinmax\fP is executed
between the execution of \%\f3glBegin\fP and the corresponding
execution of \%\f3glEnd\fP.
.P
\%\f3GL_INVALID_OPERATION\fP is generated if \f2types\fP is one of
\%\f3GL_UNSIGNED_BYTE_3_3_2\fP,
\%\f3GL_UNSIGNED_BYTE_2_3_3_REV\fP,
\%\f3GL_UNSIGNED_SHORT_5_6_5\fP, or
\%\f3GL_UNSIGNED_SHORT_5_6_5_REV\fP
and \f2format\fP is not \%\f3GL_RGB\fP.
.P
\%\f3GL_INVALID_OPERATION\fP is generated if \f2types\fP is one of
\%\f3GL_UNSIGNED_SHORT_4_4_4_4\fP,
\%\f3GL_UNSIGNED_SHORT_4_4_4_4_REV\fP,
\%\f3GL_UNSIGNED_SHORT_5_5_5_1\fP,
\%\f3GL_UNSIGNED_SHORT_1_5_5_5_REV\fP,
\%\f3GL_UNSIGNED_INT_8_8_8_8\fP,
\%\f3GL_UNSIGNED_INT_8_8_8_8_REV\fP,
\%\f3GL_UNSIGNED_INT_10_10_10_2\fP, or
\%\f3GL_UNSIGNED_INT_2_10_10_10_REV\fP
and \f2format\fP is neither \%\f3GL_RGBA\fP nor \%\f3GL_BGRA\fP.
.SH SEE ALSO
\%\f3glMinmax(3G)\fP,
\%\f3glResetMinmax(3G)\fP,
\%\f3glGetMinmaxParameter(3G)\fP
